The Nissan 370Z and the BMW Z4 are two seriously sporty offerings headed in two different directions. The Z4 is softer, heavier and more stylish than its predecessor, while the 370Z is harder, lighter and takes some risks with its exterior. The 370Z is a coupe (although it available in a drop-top), and the Z4 has a stow-able aluminum roof. The BMW is a genuine luxury car offering, while the 370Z sits on the lot next to the Quest and the Versa. However, the two vehicles share similar dimensions and performance numbers, and both contain the letter "zed," giving Top Gear enough reason to pit the two coupes against each another on the test track.